linux-kernel - Re: [PATCH v2 1/3] mm/shmem: check return value of shmem_init

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 6 Jun 2022 09:34:13 +0800
From:   Chen Wandun <chenwandun@...wei.com>
To:     Matthew Wilcox <willy@...radead.org>
CC:     <hughd@...gle.com>, <akpm@...ux-foundation.org>,
        <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        <david@...hat.com>, <wangkefeng.wang@...wei.com>
Subject: Re: [PATCH v2 1/3] mm/shmem: check return value of
 shmem_init_inodecache



On 2022/6/5 19:49, Matthew Wilcox wrote:
> On Sun, Jun 05, 2022 at 11:55:55AM +0800, Chen Wandun wrote:
>> It will result in null pointer access if shmem_init_inodecache fail,
>> so check return value of shmem_init_inodecache
> You ignored my suggestion from v1.  Here, let me write it out for you.
Hi Matthew,
I didn't ignore your suggestion,  some explanation is needed, sorry for 
that.

In V1, Kefeng point:
"kmem_cache_create return a pointer to the cache on success, NULL on 
failure,
so error = -ENOMEM; is right :)"

so, I look some similar code such as init_inodecache in kinds of file 
system,  they all
return -ENOMEM on failure, so is it OK to return -ENOMEM on failure :)

Besides,  kmem_cache_create return NULL on failure, maybe returning 
error code
on failure is more proper, but it is another job.
>
> +static int shmem_init_inodecache(void)
>   {
>    	shmem_inode_cachep = kmem_cache_create("shmem_inode_cache",
>    				sizeof(struct shmem_inode_info),
>    				0, SLAB_PANIC|SLAB_ACCOUNT, shmem_init_inode);
> +	if (!shmem_inode_cachep)
> +		return -ENOMEM;
> +	return 0;
>   }
>
> ...
>
> +	error = shmem_init_inodecache();
> +	if (error)
> +		goto out2;
>
>
> .